Wu Geng-Bo, Zhu Shu-Yan, Pang Stella W, Chan Chi Hou
State Key Laboratory of Terahertz and Millimeter Wave, City University of Hong Kong, Hong Kong 999077, China.
Department of Electrical Engineering, City University of Hong Kong, Hong Kong 999077, China.
Nanophotonics. 2022 Sep 6;11(20):4499-4514. doi: 10.1515/nanoph-2022-0352. eCollection 2022 Sep.
Metasurfaces have attracted significant attention in recent years due to their unprecedented light-manipulation abilities. However, most metasurfaces so far have relied on external light excitation, prohibiting them from full on-chip integration. Inspired by the superheterodyne principle in radio communications, here we propose a new waveguide-integrated metasurface architecture capable of converting in-plane guided modes into any desired out-of-plane free-space modes. A theoretical model, verified by simulation and experiment, is developed to provide a deep understanding of the involved physical mechanism and facilitate innovative metasurface designs. The judicious design of baseband signals allows the silicon-based superheterodyne metasurfaces to achieve complex light manipulations, including arbitrary-direction beam deflection and focusing. The proposed superheterodyne metasurface is a marriage of radio communications and photonics. It provides a paradigm shift of metasurface designs and empowers integrated photonic devices with extraordinary free-space interactivity capability, enabling a broad spectrum of applications in communications, remoting sensing, and imaging.
近年来，超表面因其前所未有的光操控能力而备受关注。然而，迄今为止，大多数超表面都依赖外部光激发，这使得它们无法完全集成到芯片上。受无线电通信中的超外差原理启发，我们在此提出一种新的波导集成超表面架构，该架构能够将面内导模转换为任何所需的面外自由空间模式。我们开发了一个经过仿真和实验验证的理论模型，以深入理解其中涉及的物理机制，并促进创新的超表面设计。通过对基带信号的巧妙设计，基于硅的超外差超表面能够实现复杂的光操控，包括任意方向的光束偏转和聚焦。所提出的超外差超表面是无线电通信与光子学的结合。它为超表面设计带来了范式转变，并赋予集成光子器件非凡的自由空间交互能力，从而在通信、遥感和成像等领域实现广泛应用。
